The present disclosure relates generally to microfluidic devices, and to fluid ejection devices incorporating the same.
Inkjet printbars and other fluidic microelectromechanical systems (MEMS) components often include a microfluidic device. Such microfluidic devices are generally formed of ceramic materials or multi-layer metal and/or ceramic materials. Methods of forming microfluidic devices aim to address fundamental issues, including, but not limited to the following: attaching the die to the device with accurate alignment and planarity; achieving fluid interconnect across several orders of magnitude without color mixing between slots; achieving electrical interconnect; forming a device that withstands ink or other fluid attack; and forming such a device in an economical manner.
Satisfying a few of these issues may be possible with any one material or design, however, it remains difficult to satisfy all of the above issues. As an example, multi-layer ceramics are highly flexible in 3D fluidic and electrical interconnect, but are relatively expensive to manufacture. As another example, ceramic devices may be limited in slot pitch and mechanical tolerance, which may render them mis-matched to typical MEMS-fabricated silicon dies. While polymeric materials are relatively inexpensive, they generally are not capable of withstanding prolonged exposure to ink. Furthermore, polymeric materials, in some instances, are not able to maintain their shape when a silicon die is used, in part because of the coefficient of thermal expansion (CTE) mismatch and low modulus.